Pulp-molding machine and method of forming molded pulp articles



.A Pllz, 1929' M. P. cHAPLxN 1,707,430

PULP MOLDING MACHINE AND METHOD OF FORMING MOLDED PULP ARTICLES Filed Feb. v, y192'/ v 2 sheets-sheet i -BY 1 man m/g/ Y f ATT mms- April 2, 1929. M. P. CHAPLIN 1,707,430

Y PULP HOLDING MACHINE AND METHOD 0F FORMING MOLDED PULP ARTICLES Fi1ed.Feb.7, 1927 v -2 sheets-sheet 2 INVENTOR ATTO EYS l Patented Apr. 2, 1929.

UNITED. STATES PATlazNT orFicE.-

l MERLE r.'cHArLIN, or WHITE PLAINS, NEw YORK, AssIGNoR, BY MEsNE .ASSIGN- MENTs, To EIDELITY TRUST COMPANY, TRUSTEE, or PORTLAND, MAINE, A coRro- RATION OF MAINE.

:PULP-MODDING MACHINE AND METHOD or EORMING MOLDED rULr ARTICLES.

t. Application led February 7, 1/927. SeraljNo. 166,364.

This invention relates to pulp molding -machines and methods of forming molded pulpv articles, and 'more particularly to the construction ofthe forming and compresslon s dies.

In molding articles `from pulp, before the articles are pressed, there is a fillet or de- -posit of pulp at the outer edge portion of In some machines, thisA the forming die. fillet or deposit is squeezed out and extends outwardly from the pressed article in thel form of a feather edge. l

This invention has for its salient ob]ect to provide 'a structure whereby all the pulp deposited on the forming dies will be pressed by the compression dies into the article and whereby the articles molded by the .compression dies on the forming dies will have a clean and well-defined outer edge.

'Another object of the invention is to produce a molded article having its outer edge reinforced or thicker than the remaining portion of the article.

Further objects of the invention will appear from the-following specification Ataken in connection with the drawings, which form a part of this application, and. in which Fig. 1 is an .elevational view illustrating one form of forming dies and compression dies;

Fig. 2 is taken through one of theforming dies and the compression vdie coacting therewith;

Fig. 3 is an enlarged sectional `elevation showing thedetails of construction of the l coacting portions of the forming and compression dies;

Fig. 4 is an enlarged sectional elevation showing portions of the outer edge of the 4o forming die and compression die prior to the compression of the pulp therebetween; and

Fig. 5 is a view'similar to Fig; 4 but showing the pulp .compressed between the two dies.

so constructi'ngy and operating the forming and compression dies that these-elements are broughtinto spaced parallel relation prior to the'movement of the compression die into coacting relationwith the forming die. Furthermore, theforining die is provided -at its outer periphery with an annular, relatively deep ring and the compression die is proan enlarged sectional elevation .The invention brieliydescribed consists-of vided with an annular, relatively deep projectingportion adapted tolfit closely within the ring on the forming die. Since the forming dies and compression dies are brought together in parallelism instead of by a swinging motion, the rings on the forming dies and the projections on the compression dies can be made of such dimensions as to force Vinto the mold formed between the dies, the ma` terial deposited at the outer edge of the mold, thus compressing all of this material into the f mold. Further details of the invention will appear from the following description.

Any desired construction of forming die carrier and compressiondie carrier may be utilized, but in the form of the invention illustrated, the construction shown is that illustratedl and described in my application Serial No. 129,130 filed August. 14, 1926. In this embodiment of the invention, the forming dies 1() are carried by arms 11 mounted on a shaft 12 and are adapted to' rotate through a pulp solution contained in a vat 13. y

Each of the arms 11 has a conduit 15 therethrough having its inner end 16 adapted to coa-ct with a suction and air control casing inl .such a manner that the forming dies will be vp'erforations 27 therein are carrie by toggle arms' or yokes 21 pivoted on pintles 22 mounted in pivot slots 23 formed at the outer ends' of arms .24 carried by a hub 25kmounted on the sha-ft 26. A yoke 30 is mounted on each of the pins22 and is engaged by, a compression spring 314 interposed between the yoke co-pending and a collar 32 adjustably threaded on'a bolt 33 carried by a transverse member 34 formed 'on the arm 24.

Each of theyokes 21 has secured thereto and projecting therefrom a bracket 35 which carries a pair of rollers 36 disposed on op osite sides of a cam track 37. The track 3 is so designed that the approaching forming and compression dies will be disposed in axial alinement and with theirfaces in parallel reformed in the face of the die.

lation. In other Words, the forming and compression dies are brought into spaced parallel relation' prior to their movement toward each other into coacting relation. `This construction and operation is more fully described in the application above referred to. It will be noted that the openings 27 through the face of the compression dies are substantially allithe same length and are su'iciently short to prevent their retaining any considera-ble amount of moisture or water. VThe particular construction of the forming and compression dies is'illustrated in Figs. 3, 4 and 5. In these vfigures it will be seen that the forming die 10 lhas a screen 40 secured to its outer surface over the perforations 41 The screen is secured in position by a ring 42 which is relatively 'deep and has a cylindrical surface 43 and a curved surface 44.

The compression die 20 is formed with an annular relatively long projection 48 having a cylindrical surface 49 adapted to lit closely Within the cylindrical surface 43 'of the ring 42.

From the showing in Figs. 3 and 5 it will be noted that the space .A between the outer edge portion of the projection 48 and the'coacting portion of the compression die is wider than the space B between the remaining coactin portions of the two dies.

In ig. 4 the pulp formed on the forming die is shown with a fillet or deposit 50 at the` outer periphery thereof which adheres to that portion -of the surface 43 which is nearest the screen 40. Since the forming die and compression die come into coacting relation in axial alinement or with their surfacesparallel, the fillet or deposit will be pressed between the two dies and Will be prevented from spreading laterally to form a feather edge on the article.

It will be'understood that the cylindrical surface 43 of the ring 42 is made sufficiently 'deep to surround and toextend beyond the fillet or deposit 50 an'd to confine this material when the projection 48 of the compression die '50' is forced Within the ring 42.4

In Fig. 5 it will be seen that the outer edge portion 51 of the pulp article is thicker than the remaining portion thereof and that the .fillet or deposit 50 has been pressed into the article.`` Furthermore, the edge portion 50 may by properly proportioning the parts be made denser than the remaining portions.

Although one specific-embodiment of the invention has been particularly shown and described, it will be understood that the invention is capable of modification and that changes in the construction and in the ar rangement of the various cooperating parts may be made Without departing from the spirit or scope of the invention, as expressed in the following claims.

What I claim is:

1. vIn a pulp molding machine, a forming die, a compression die, means for bringing said dies -into spaced parallel relation and for subsequently moving said dies into coacting pressing relation, said forming die having a peripheral ring having a substantially cylindrical inner surface and said compression die having a peripheral projection having a substantially cylindrical outer surface adapted to fit Within the cylindrical surface of the ring and to confine and compress Within the ing relation, rings on the forming dies surl rounding said dies and annular projections on the compression dies adapted to fit Within Said rings and to confine and compress within the rings the fillet or deposit of pulp disposed around the peripheries of the dies.

3. In a pulp molding machine, a forming die, and a compression die adapt-ed to coact therewith to form a molded article, the coacting surfaces of said dies being spaced apart a greater distance at their outer edge portions than at the remaining portions thereof when the dies are disposed in coacting molding relation, whereby the article molded thereby Will have its edge portion thicker than the remaining portion thereof.

4. In a pulp molding machine, a forming die, a ring carried by and disposed at the outer periphery ofthe forming die and extending beyond the face of the die, said ring having a cylindrical inner surface at least as deep as the depth of pulp on the forming die prior to the compression thereof.

5. In a pulp molding machine, a forming form a molded article, and said compression die having an annularprojection provided with a cylindrical outer surface adapted to fit Within the cylindrical surface of the ring and force all of the pulp at the outer edge of the forming die into the molded article.

6. A method of forming the edge of a molded article Which consists of depositing on a forming die a layer of pulp having an excess of material at the outer edge thereof and confining and compressing said edge to form a reinforced edge.

7. A method of forming molded pulp articles which consists of forming a pulp blank with an excess of pulpat the margin thereof and in consolidatin and compressing the marginal excess to orm a reinforced edge without increasing the thickness of the main body portion of the article.

8. A method of forming molded pulp articles which consists of forming a pulp blank with an upstanding excess of pulp at the margin thereof and in consolidating and compressing the marginal excess to form a reinforced edge without increasing the thickness 10 of the mam body portion of the article.

9. A molded pulp article having a. main bdy portion and a reinforced homogeneous e ge. v

In witness whereof, I have hereunto set my 15 hand this 3rd day of February, 1927.

MERLE P. CHAPLIN. 

